Door structure for mixers



March 24, 1942- cs. JAEGER ET AL DOOR STRUCTURE FOR MIXERS Filed Aug. 2,1940 3 Sheets-Sheet 1 Jaeger glar znce l. men W INVENTORS Gebhard Bohhrls 6r$1. (kW ATTORNEYS March 24, 1942.

G. JAEGER ET AL DOOR STRUCTURE FOR MIXERS Filed Aug. 2, 1940 3Sheets-Sheet 2 INVENTORS m 0 5 5 Y E .wN m 5 q CA C-icbhard Jnz Clargnczl.

March 24, 1942. G. JAEGER ET AL 2,277,518

DOOR STRUCTURE FOR MIXERS Filed Aug. 2, 1940 3 Sheets-Sheet 5 INVENTORSGebhard Jaeger Clarence I- B h Chris Gerst ATTORNEYS Patented Mar. 24,1942 UNITED STATES PATENT OFFICE DOOR STRUCTURE FOR MIXERS GebhardJaeger and Clarence I. Bohmer, Columbus, Ohio; and Chris Gerst, Detroit,Mich.', assignors to The Jaeger Machine Company, Columbus, Ohio, acorporation of Ohio Application August 2, 1940, Serial No. 349,556

2 Claims Our invention relates to a door structure for mixers. It has todo, more particularly, with the discharge door structure of a concretemixer of the truck mixer type although it is not necessarily limitedthereto.

One of the objects of our invention is to provide a door structure for atruck mixer which is of such a nature that the door may be easily andquickly opened or closed with little effort.

Another object. of our invention is to provide a door structure fortruck mixers which is of such a nature that it may be controlled from apoint remote from the door which may be in a convenient location for theoperator.

Another object of our invention is to provide a door structure for truckmixers which is of such a nature that when itis closed it will beeffectively locked.

Another object of our invention is to provide a door structure which isvery effective but which is of a simple structure so that it can bemanufactured at a low cost.

Another object of our invention is to provide a door structure of thetype indicated which has means associated therewith for cleaning thedoor seat as the door approaches closed position so that it willeffectively seal the door opening.

In its preferred form, our invention contemplates the provision of adoor structure associated with the discharge opening of a truck mixer.This door structure is mounted in association with the Opening formovement between closed and open positions. We provide vacuum operatedmeans for controlling movement of the door between these two positions.The control for this vacuum operated means may be located at anysuitable point convenient to the operator.

The preferred embodiment of our invention is illustrated in theaccompanying drawings wherein similar characters of reference designatecorresponding parts and wherein:

Figure 1 is a side elevation of a truck mixer showing our door structureapplied thereto.

Figure 2 is a side elevation of the rear portion of the truck mixershowing in detail the door structure. I

Figure 3 is a plan view of the structure shown in Figure 2.

Figure 4 is a detail of a portion of the door structure being mainly insection.

Figure 5 is a perspective view of the rear end of the truck mixershowing the door in open position. a

Figure 6 is a modification of the structure shown in Figure 4.

Figure 7 illustrates a modified form of our door structure.

Figure 8 illustrates means for rotating the door as it nears closedposition to clean the door seat.

With reference to the drawings we have illustrated in Figure 1 a truckmixer which includes a rotatable mixing drum l of the usual type drivenby means of a power unit 2 in the usual manner. The rear end of themixing drum has a discharge opening 3 (Figure 5) with which our doorstructure is adapted to be associated. Surrounding the opening 3 is aninclined annular flange 4 which is adapted to serve as a seat for thedisk-like door 5. Supported centrally within the drum I is a watersupply pipe 6. The rear end of this water supply 6 is adapted to supportthe disk door 5.

For mounting the door 5 on the pipe 6 for movement between closed andopen positions, we preferably provide the structure illustrated best inFigure 4. As shown in this figure, the disk '5 has attached thereto at acentral point a casting 5a which has an integral hub portion 1. The pipe6 receives the forward end 8 of a shaft 9. The end 8 of the shaft 9 issuitably secured in position within the pipe 6 and is prevented fromrotating relative to the P pe. The hub 1 fits around the rear end of thepipe 6 and is rotatable thereon. A ball bearing 10 is provided betweenthe rear portion of the hub and the shaft 9. This ball bearing structureserves as a thrust bearing against which bears the forward end of asleeve II. This sleeve is mounted for longitudinal movement on the shaft9. The forward end of the sleeve II has a peripheral flange l2 formedthereon. This flange is engaged by a collar I3 which is secured to thehub l by means of the bolts M. The collar l3 serves to keep the forwardend of the sleeve II in association with the bearing i0 and to connectthe sleeve II and the door 5 together. It will be apparent that the doorcan be readily rotated relative to the sleeve II. It will also beapparent that movement of the sleeve ll axially of the shaft 9 willproduce a corresponding axial movement of the door 5 relative to theshaft 9 and the pipe 6. The bearing ill will move with the door 5. Axialmovement of the door 5 will seat it on or unseat it from the seat 4 asillustrated best in Figure 2. This will close and open the dischargeopening 3. g

For controlling the movement of the door 5 between open and closedposition, we provide vacuum actuated mechanism. This mechanism includesa vertical lever l5 which is pivoted ing the upper end of a piston rod3|.

termedlate its ends as at It to a rearwardly extending horizontallydisposed bifurcated arm II. The arm I! is carried on the upper end of asupporting frame It. The lower end of the lever I5 is provided with ayoke portion I! which straddles the outer end of the sleeve ll. Links 23are pivotally connected to the outer ends of the legs of the yokeportion I! as at 2| and at diametrically opposed points 22 to the sleeveII. It will be apparent that by swinging the upper end of the lever II,the sleeve ll and, conse-.

quently, the door 5 will move axially.

For swinging the upper end of the lever l3, we provide a toggle jointstructure. One link of the toggle is formed by an adjustable link ortumbuckle 23 which is pivoted to the upper end of the lever l5, as at24. The other end of the link 23 ispivoted'to the rear end of a lever 25as at 23. The lever 25 has its forward end keyed to a transverselyextending shaft, which is rotatably mounted in the supporting frame l3.One end of the shaft 21 has a sleeve 2l'keyed thereon. This sleevecarries an integral arm 23. The arm 23 has its outer end pivotallyconnected at 30 to This piston rod 3! has its lower end connected to apiston 32 (Figure 2) which is adapted to move within a verticallydisposed vacuum cylinder 33. The cylinder 33 has its lower end pivotallyconnected at 34 to a bracket suitably secured to the frame It.

Upward movement of the piston 32 in the cylinder 33 will produce aclosing movement of the door 5. This will cause the arm 28 to swingupwardly, rotating shaft 21 and swinging the rear end of the lever 25downwardly. This will push the link 2'3 rearwardly and will swing theupper end of the lever. l5 rearwardly and its lower end forwardly.Swinging of the lower end of lever l5 forwardly will produce a forwardthrust on the links 20 and, consequently will move the door 5 onto itsseat 4. As previously stated, lever 25 and link 23 serve as a togglelink structure and when the pivot point 26 moves downwardly past center,the door will be locked automatically in closed position. Thus, it willnot be necessary to keep the vacuum on when the door is closed in orderto keep it closed. Downward movement of the piston 32 in the cylinder 33will cause upward swinging of lever 25, as indicated by the dotted linesin Figure 2, a forward pull on link 23, forward swinging of the upperend of lever l5 and rearward swinging of the lower end thereof. Thiswill exert a rearward pull on the links 20 and, consequently, will movethe door 5 rearwardly ofl its seat. During movement of arm 23 thecylinder 33 will swing about its pivot 34.

For supplying vacuum to the cylinder 33 we provide'a vacuum tank 35.This tank may be connected by a line 35 to the manifold of the powerunit 2 which is an internal combustion engine. However, if desired, theline 36 may be connected to a vacuum pump driven by the unit 2 or by themain power unit of the truck mixer. A vacuum line 31 leads from the tank35 and is connected to a control valve 38. The control valve 331sconnectedby a flexible conduit 39 to the upper end of the cylinder 33and by a flexible conduit 43 the lower end of the cylinder. The controlvalve is such that when it is in one position the line 39 is connectedto the line 40 so that vacuum will serve to lift the piston 32 and closethe door 5. Atthesame time, the valve causes the line 40 to communicatewith the atmosphere.

In the other position of the valve, the line 31 is caused to communicatewith the line 45, producing vacuum in the lower end of the cylinder 33and drawing the piston "downwardly, the valve causing the line 33 tocommunicate with the atmosphere at the same time.

Thus by merely operating the valve 33, the door may be closed or opened.When closed, it will be locked in closed position. The vacuum willnormally hold the door closed when the unit 2 is operating. However, ifthe unit 2 does'not operate, the door will still be locked in closedposition by the toggle linkage. The sleeve 23 which carries the arm 23is provided with an integral socket 4| for receiving a bar or lever bymeans of which the door may be manually operated.

If any material adheres to the seat 4, it is desirable to rotate thedoor 5 relative to the seat to clean the seat during the closingoperation. The bearing structure III will permit this rotation. The door5 is provided with a handle or knob 517 on its outer surface adjacentits periphery to facilitate this rotation. when the drum I rotates, thedoor 5 rotates therewith. The door rotates relative to the sleeve II andthis relative rotation is facilitated by the bearing i0.

In Figure 8, we have illustrated means for automatically producing thisrotation as the door nears closed position. In this instance, the shaft3b is provided with a helical groove-42 which is engaged by a ballcarried by a support 43 rigidly secured to the interior of the hubportion 1b of the door. The groove 42 is almost straight throughout thegreater portion of its length but extends at a sharp angle, relative tothe axisof shaft so, at its inner end. Consequently. as the door ismoved inwardly by the thrust applied to the sleeve llb, it will notrotate to any ap preciable extent until the ball carried by member 43reaches the inner portion of groove 42, at which time the door will begiven a quick turn. At this time, the door will be substantially incontact with seat 4 and, consequently, any grout on the seat will bewiped off and there will be a better seal produced.

Ordinarily, water is suppliedto the mixer from a supply tank at theforward end thereof which is connected to the pipe 6. However, becausethe sleeve ll does not rotate, it is easy to connect a pipe in to. therear end thereof, as indicated in Figure 6 for supplying water to themixer. In this instance, the shaft 90 will be hollow so that it willconduct the water to the pipe 5.

In Figure 7 we show a modification of our structure. In this instance,we provide a somewhat different arrangement for operating the door. Avacuum cylinder 33a is provided but is horizontally disposed atthe topof the mixer. This piston rod is connectedto the upper end of a leverl5a by means of a link 23a. The lever lie is pivoted adjacent its lowerend as at "a. The lower end of the lever I50 is connected to the doorstructure by means of links 20a. The pivot I50 is carried on the outerend of a horizontal support Ila secured to the rear end of the mixer.

This structure will function similarly to that previously described. Byoperating the valve 38a, the lever l5a will be swung about its pivotIlia to move the door between closed and open positions.

It will be apparent from the preceding description, that we haveprovided a door structure having many advantages. It is of such a naturethough the structure is very effective, it is very simple.

Various other advantages will be apparent from the precedingdescription, the drawings and the following claims.

Having thus described our invention, what we claim is:

1. In combination, a mixing drum mounted for rotation, said drum beingprovided with an opening in one end thereof, a door associated with saidopening, said door being slidably mounted for axial movement on asupport disposed centrally of said opening, said door being adapted torotate with the drum, means for moving said door axially of said supportto open or close said opening, said means including a movable controlmember mounted adjacent said door, means for connecting said controlmember to said door in such a manner as to permit relative rotation ofsaid door, said door and said support being provided with cooperatingportions which engage each other to produce positive rotation of thedoor as it approaches closed position.

2. In combination, a mixing drum mounted for rotation, said drum beingprovided with an opening in one end thereof, a door associated with saidopening, said door being slidably mounted for axial movement on asupport disposed centrally of said opening, said door being adapted torotate with the drum, means for moving said door axially of said supportto open or close said opening, said means including a movable controlmember mounted adjacent said door, means i'or connecting said controlmember to said door in such a manner as to permit relative rotation ofsaid door, said door and said support being provided with cooperatingportions which engage each other to produce positive rotation of thedoor as it approaches closed position, and a vacuum actuated unitconnected to said movable control member for moving said door.

GEBHARD JAEGER. CLARENCE I. .BOHMER. CHRIS GERST.

